Problem: Simplify the following expression: $x = \dfrac{k - 4}{7k} - \dfrac{6k + 3}{7k}$
Explanation: Since the expressions have the same denominator we simply subtract the numerators: $x = \dfrac{k - 4 - (6k + 3)}{7k}$ Distribute the negative sign: $x = \dfrac{k - 4 - 6k - 3}{7k}$ Combine like terms: $x = \dfrac{-5k - 7}{7k}$